Why there is engine power difference between baleno and scross whereas both are 1.3 ltr engine

@SVP why there is engine power difference between baleno and scross whereas both are 1.3 ltr engine

Question asked from: http://www.carandbike.com/

Different engine tuning. Same engine used by Swift, Dzire, Zest, Punto etc etc! All with varying tuning and outputs.
SVP